This invention relates to copolycarbonates having a 2-methylepichlorohydrin residue incorporated therein.
It is known from U.S. Pat. Nos. 3,136,741 and 3,161,615 to make polycarbonate copolymers by reacting 4,4'-dihydroxy diphenyl methanes with phosgene and various glycols such as ethylene glycol, butane glycol, and hexane glycol.
It is also known from U.S. Pat. No. 3,220,973 to use glycerine, trimethylolpropane, pentaerythritol, etc. in place of the above glycols to prepare crosslinked polycarbonates.
It is also known from Ser. No. 374,858 filed June 29, 1973 now abandoned in favor of Ser. No. 638,393, filed Dec. 8, 1975 that copolycarbonates can be prepared having an epihalohydrin residue incorporated therein, however, these have the disadvantage that they crosslink upon heating to about 240.degree. C. and thus cannot be used in a standard molding apparatus.
It is also known from U.S. Pat. No. 3,875,112 (Bockmann) that low molecular weight copolycarbonates can be prepared by reacting bisphenol A, the glycerine bis ether of bisphenol-A, and phosgene under polycarbonate forming conditions. These low molecular weight polycarbonates have active hydroxyl functionalities and it is taught that they can be used as prepolymers for further reaction to form urethane/polycarbonates, polyester polycarbonates, etc. The high molecular weight polycarbonates containing epihalohydrin residues as taught in Ser. No. 374,058 (above) would have identical functional groups. It has been shown that these polymers crosslink at temperatures above about 250.degree. C. and cannot be used in standard molding apparatus.
It is further known from U.S. Pat. No. 3,992,357 that copoly-carbonates can be made having a residue of di(2-methyl glycidyl) ether of Bis A incorporated therein; however, these copolymers degrade and discolor under certain molding conditions and could not be used to prepare clear plastic articles.